Introduction to Chemistry. “The world is full of obvious things. Which nobody by any chance ever observe.” -- Sherlock Holmes. Careful observation is the foundation of chemistry as an experimental science, leading us to question what we have observed – how, what why?
1.33 → 1.3
1.36 → 1.4
5.5 yards = 1 rod
40 rods = 1 furlong
8 furlongs = 1 mile
1 meter = 39.37 inches
1 yard = 36 inches
***do not get confused!!!
How fast is a car going 35 miles/hour going in yards/second?
1 mile = 1760 yards;1 hour = 60 minutes; 1 minute = 60 seconds
When converting with metric, always use that value of the unit as compared to the base unit
Science fiction often uses nautical analogies to describe space travel. If the starship U.S.S. Enterprise is traveling at warp factor 1.71, what is its speed in knots?
Warp 1.71 = 5.00 times the speed of light
The speed of light = 3.00 x 108 m/s
1 knot = 2000 yd/hr
1. Converting from °C to Kelvin
TC = TK – 273.15
TK = TC + 273.15
TF = TC x 9°F + 32°F
TC = (TF - 32°F)5°C
1. Normal body temperature is 98.6°F. Convert this to the Celsius and Kelvin scales.
2. Liquid nitrogen, which is often used as a coolant for low-temperature experiments has a boiling point of 77 K. What is this temperature on the Fahrenheit scale?
density of ethanol = 0.789 g/cm3
1 gal = 3.78 L
1 lb = 454 g
In the opening scenes of the movie Raiders of the Lost Ark, Indiana Jones tries to remove a gold idol from a booby-trapped pedestal. He replaces the idol with a bag of sand of approximately the same volume. (density of gold = 19.32 g/mL; density or sand = 2 g/mL)
1. the solute – the part that is dissolved
2. the solvent – the part that does the dissolving
WATER IS THE UNIVERSAL SOLVENT!!
We also use properties to describe matter
1. Chemical energy – released as heat energy
2. Nuclear energy
3. Mechanical energy
4. Electrical Energy
5. Light energy
6. Radiant energy (not a property of objects) – the transfer of
energy through empty space
* has no fixed volume or shape
* it takes the shape of the container by either
compression or expansion
Energy of the system
q = (m)(ΔT) (Cp)
q – energy change
m – mass
ΔT – Tfinal – T initial
Cp – specific heat
How much heat is lost when a solid aluminum ingot with mass 4100 g cools from 660.0 °C to 25 °C?
q = ?
m = 4100g
ΔT = (660 – 25) = 635°C
Cp = 0.900 J/g°C
q = 4100g 635°C 0.900J = 2.35 x 106 J